# Les étuis EVA peuvent-ils offrir une protection ESD pour l'électronique ?

Canonical URL: https://evacasemanufacturer.com/fr/news/can-eva-cases-provide-esd-electrostatic-discharge-protection-for-electronics
Published: 2026-05-14 12:47:00
Author: Dongguan Lianping Luggage Co., Ltd.
Publisher: LIANPING
Keywords: esd safe eva case, antistatic eva case manufacturer, surface resistivity eva case, iec 61340-5-1 packaging, static dissipative foam insert, carbon loaded eva, esd case moq 1000
Views: 1 044
Language: fr

L'EVA standard est un isolant. Voici ce que réalisent les compounds EVA antistatiques, la plage de résistivité selon IEC 61340-5-1, et quand un sac de blindage reste nécessaire.

Standard EVA is an insulator, and a good one. Surface resistivity on our untreated shell material sits above 10^13 ohms per square, which means a case made from it holds charge rather than bleeding it off. That matters when the contents are a bare PCB, a sensor module or a drive with exposed contacts. It matters much less when the contents are a finished consumer product already sitting in its own housing.

## What changes when you need ESD control

The fix is in the material, not the shape. Adding carbon black or a permanent antistatic masterbatch to the EVA compound brings surface resistivity into the dissipative band, roughly 10^5 to 10^9 ohms per square, which is the range IEC 61340-5-1 uses for protective packaging. A topical antistatic coating is the cheaper route, but coatings wear off with handling and humidity swings, so for a case opened daily we recommend the loaded compound.

Two things have to be checked on the finished case, not only on the raw sheet. Surface-to-surface resistance across the shell, and the resistance path from the case to whatever it is standing on, since a dissipative shell resting on an insulating bench still collects charge from the person carrying it. Our QA bench measures both at 100 V and 500 V, at 12% and 50% relative humidity, and the readings go on the inspection sheet with the lot number.

## Where the limits are

A dissipative EVA case slows charge decay. It is not a Faraday cage and it will not stop a direct discharge into a connector. If the contents are sensitive at that level, the case needs a conductive inner layer or a metallized shielding bag inside the foam cavity, and the usual answer is both: an antistatic shell plus a shielding bag around the board itself. Colour is the other constraint. Carbon-loaded EVA comes in black or dark grey, so a buyer who needs a white or colour-branded shell has to accept a topical coating, and that coating is measured in months rather than years.

Humidity moves the numbers more than buyers expect. A compound that reads 10^7 ohms at 50% RH can read two orders of magnitude higher at 12% RH, which is a real condition inside a heated European warehouse in January. We test at both ends and ask buyers which end their product will actually see before quoting a compound.

## How it gets specified

Tell us what goes in the case and which standard the receiving end audits to. Most ESD programs are written to IEC 61340-5-1 or to ANSI/ESD S20.20, and the two ask for slightly different documentation. We supply material test reports with the resistivity figures and the humidity they were measured at, and we build the [electronic accessory case](https://evacasemanufacturer.com/fr/products/sub/eva-case-for-electronic-accessories) with a die-cut antistatic foam insert so the whole interior sits in the dissipative band rather than just the shell. Drawings and target values can go through [the contact page](https://evacasemanufacturer.com/fr/contact) before quotation.

MOQ on antistatic compounds runs higher than standard, usually 1,000 pieces, because the compound has to be run as a dedicated lot rather than pulled from standard sheet stock. Sampling takes about a week longer for the same reason. The job next on the bench is a sensor module case with a 10^6 ohm target; the first molded shells are due off the press on Friday and go straight to the resistance bench.

## FAQ

**Is EVA naturally antistatic?**

No. Untreated EVA measures above 10^13 ohms per square at the surface, so it is an insulator and will hold a static charge. To make a case static dissipative, the compound is loaded with carbon black or a permanent antistatic masterbatch, which brings surface resistivity into the 10^5 to 10^9 ohms per square range used by IEC 61340-5-1.

**What surface resistivity should an ESD-safe EVA case have?**

Static dissipative packaging is generally specified between 10^5 and 10^9 ohms per square, measured at a defined humidity. LIANPING tests finished shells at both 100 V and 500 V under 12% and 50% relative humidity, because resistivity can shift by two orders of magnitude between those conditions. Test reports are issued per lot.

**Can an antistatic EVA case replace a shielding bag?**

Not entirely. A dissipative shell slows charge decay and prevents the case itself from generating charge, but it does not block a direct discharge into an exposed connector. For bare boards or sensitive modules, use a metallized shielding bag inside the foam cavity along with the antistatic shell. Carbon-loaded EVA is also limited to black or dark grey.

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